Low dosage and long treatment duration of beta-lactam: risk factors for carriage of penicillin-resistant Streptococcus pneumoniae.
BACKGROUND
The spread of drug-resistant Streptococcus pneumoniae in the community is a public health problem in developed and developing nations, but whether antibiotic use is responsible for the increase in drug resistance is not known.


OBJECTIVE
To analyze the relationship between penicillin-resistant S pneumoniae (PRSp) pharyngeal carriage and characteristics of beta-lactam use.


METHODS
Observational study of children attending 20 randomly sampled schools.


METHODS
The Loiret, in the center of France.


METHODS
A total of 941 children, 3 to 6 years old.


METHODS
Pharyngeal carriage of S pneumoniae, antibiotic use, and medical events during the preceding 30 days. Pneumococcal penicillin G sodium minimal inhibitory concentrations and serotyping were performed.


RESULTS
Medical illnesses and the use of antibiotics were not associated with PRSp carriage. However, oral beta-lactam use was associated with an increased risk of PRSp carriage (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.3; P=.03). Children treated by low daily doses of an oral beta-lactam (defined as lower than clinical recommendations) had an increased risk of PRSp carriage, as compared with children who did not (OR, 5.9; 95% CI, 2.1-16.7; P=.002). A treatment of long duration (>5 days) with a beta-lactam was associated with an increased risk of PRSp carriage (OR, 3.5; 95% CI, 1.3-9.8; P=.02).


CONCLUSIONS
Our results suggest that a low daily dose and a long duration of treatment with an oral beta-lactam contribute to the selective pressure in promoting pharyngeal carriage of PRSp.
Guillemot
D
D
Institut National de la Santé et de la Recherche Médicale, Unité 21 and Faculté de Médecine Paris Sud, Villejuif, France.
Carbon
C
C
Balkau
B
B
Geslin
P
P
Lecoeur
H
H
Vauzelle-Kervroëdan
F
F
Bouvenot
G
G
Eschwége
E
E
D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D004334:Drug Administration Schedule; D005602:France / Q000453:epidemiology; D006801:Humans; D016015:Logistic Models; D008826:Microbial Sensitivity Tests; D015999:Multivariate Analysis; D010403:Penicillin Resistance; D010614:Pharynx / Q000382:microbiology; D011008:Pneumococcal Infections / Q000188:drug therapy* / Q000453:epidemiology*; D012307:Risk Factors; D012574:Schools; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D047090:beta-Lactams